14.4.13 Error 20 (OL-1): Converter Overload
Possible reason
Solution
Long time overload
Reduce overload time, reduce load
Wrong settings of V/f curve related parameters
Adjust settings of V/f curve related parameters
Motor power and frequency converter power do not match
Motor power has to match with frequency converter power
Overload happens at lower speed
● Reduce load at lower speed
● Reduce the carrier frequency (C0.05)
● Use a frequency converter with larger power
Excessive load, excessive short Acc. / Dec. time or cycle
● Adjust load, acceleration/deceleration time or cycle
● Use a frequency converter with larger power
Low mains voltage
Check input power supply
Excessive torque compensation
Reduce torque compensation setting (C2.22) till the current
decreases
14.4.14 Error 21 (OH): Converter over Temperature
Possible reason
Solution
Frequency converter (heat sink) temperature is higher than
max. allowable temperature 85 °C
● Reduce ambient temperature, improve ventilation and
heat dissipation; clear dust, cotton wadding in air ducts;
check fan and its power supply connection (if available)
● Reduce load if necessary
● Reduce carrier frequency (C0.05)
Temperature detection circuit error
Contact with service
14.4.15 Error 22 (UH): Converter under Temperature
Possible reason
Solution
Ambient temperature is lower than -10 °C
Provide a reasonable ambient temperature that frequency
converter requires
Temperature sensor defect
Contact with service
14.4.16 Error 23 (FF): Fan Failure
Possible reason
Solution
Fan defect
Contact with service
Bosch Rexroth AG
DOK-SYTROX-DRN5020****-IT05-EN-P
128/143
Frequency-Controlled Pump Drive System Sytronix DRn 5020
Troubleshooting
